Manufacturing Process of Ethylene Dichloride

Reactions
  •  • C2H4 + Cl2  C2H4Cl2
  • • Undesired products: Propylene dichloride and Polychloroethanes.
    • Reaction occurs in a  liquid phase reactor with ethylene dichloride serving as the liquid medium and reactants reacting the liquid phase.
    • Catalyst is FeCl3 or Ethylene dibromide.
 Process Technology 

Figure. Flow sheet of production of ethylene dichloride

  • • C2H4 and Cl2 are mixed and sent to the liquid phase reactor.
  • • Here, the feed mixture bubbles through the ethylene dichloride product medium.
    • Reactor operating conditions are 50°C and 1.5 – 2 atms.
    • The reaction is exothermic. Therefore, energy is removed using either cooling jacket or external heat exchanger.
    • To facilitate better conversion, circulating reactor designs are used.
    • FeCl3 traces are also added to serve as catalyst.
    • The vapour products are cooled to produce two products namely a vapour product and a liquid product. The liquid product is partially recycled back to the reactor to maintain the liquid medium concentration.
    • The vapour product is sent to a refrigeration unit for further cooling which will further extract ethylene dichloride to liquid phase and makes the vapour phase bereft of the product.
    • The liquid product is crude ethylene dichloride with traces of HCl. Therefore, acid wash is carried out first with dilute NaOH to obtain crude ethylene dichloride. A settling tank is allowed to separate the spent NaOH solution and crude C2H4Cl2 (as well liquid).
    • The crude ethylene dichloride eventually enters a distillation column that separates the ethylene dichloride from the other heavy end products.
    • The vapour phase stream is sent to a dilute NaOH solution to remove HCl and produce the spent NaOH solution.  The off gases consist of H2, CH4, C2H4 and C2H6.

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